Anyone have any experience of installing a flush mounted CU?

I am about to start the wiring on the renovation project and have gone
for a flush mounted CU. The CU is in the downstairs cloaks and as it
has to be at an easily accessible height (1200mm) I decided a standard
CU would look a little clumsy.

The wall it will fit on(in) is the inner (blockwork) leaf of the
extension and has the meter cupboard on the outside wall.

I had thought that I would remove one of the (lightweight) blocks and
fix the new CU into the gap. However all the cable entry points are
set back a couple of cms or so from the front of the case and I cannot
see how the cables will get into the consumer unit easily (at least
without having to remove more of the blockwork above the CU, and this
seems a little dodgy to me).

One option I am exploring is to dry line the wall where the CU sits and
make the batten size sufficient as to have the cable entry holes proud
of the rest of the wall. This has the added advantage of providing
plenty of space for the cables to run behind the plasterboard and on to
the rest of the house. The only disadvantage of this I guess is the
loss of a small amount of space in the room.

Any thoughts are welcome.

Cheers

Martin
--
Martin Carroll